The benefits of using fabric glass wallcoverings are well known. Fiberglass wallcoverings offer fire resistance, easy and uncomplicated handling, and flexibility in use. They also exhibit good abrasion resistance and good appearance following painting. On the other hand fiberglass wallcoverings of the prior art require the use of special glues or adhesives with strong binding forces and require cost-intensive and time consuming painting procedures.
Typically, when covering a wall with a glass fabric, the wall as well as the fabric must be treated with a special glue or adhesive. The commonly used wet adhesive is primarily based on a starch-solution and always contains some latex binder, and must be rolled onto or sprayed onto the wall and onto the fabric. After drying, the wallcovering must be painted twice. Between the first and the second painting step the wall and the wallcovering must be dried. The paints most commonly used are standard interior wall paints, i.e., various types of latex paints.
In order to enable easy handling and the use of such wallcoverings, the woven glass fabric often is impregnated with a water-based formulation which contains mainly starch, binder and an inorganic cross-linker. The finished wall-covering typically contains up to 25 weight percent of such chemicals.
In the past, many attempts have been made to avoid the disadvantages of standard adhesives used with glass fabrics and to reduce the complexity and the time consuming procedures encountered by the end-user. WO98 14 655 describes glass fiber wallcoverings which employ a thermoplastic adhesive. Thermoplastic adhesives require a special temperature treatment which necessitates even additional equipment. The process by necessity is complicated and time consuming.
The necessary high temperature treatment can be avoided when using a self-adhesive layers as the backing layer. DE 198 11 152 describes a painted or printed glass wallcoverings with a self-sticking backing. Such systems, however, cannot be removed from the wall without the use of chemicals.
EP 0 909 850 describes a finished wallcovering with a multicolor print and a self-adhesive backing. However, self-adhesive wallcoverings are relatively expensive because they require additional production steps, e.g., the covering of the adhesive layer prior to use. In addition, the handling of such wallcoverings when applied to the wall is completely different than standard application procedures.
All such non-standard systems, mentioned above, require special materials and equipment. The handling differs significantly from standard well-known papering procedures. For paper wallcoverings a starch-based adhesive in the absence of a latex binder is most commonly used. Such starch-based adhesive can be dried and re-wetted again without a significant change in the gluing capability. The handling is easy and a special treatment in addition to rolling or spraying the paper and the wall with a paper glue is not necessary.
It is much desired in the art to provide an improved glass fabric wallcovering that keeps the good aspects of glass fabric wallcoverings, i.e., fire resistance, easy handling, flexibility, good appearance and good abrasion resistance, and which can be applied to the wall using less complicated and time consuming procedures.
It is an object of the present invention to provide a pre-glued fiberglass wallcovering which can be handled more easily when covering a wall, and which reduces the necessary processing steps for the end-user. The glass fabric has the same properties as standard fiberglass wallcoverings, in particular, excellent fire resistance.
It is another object of the present invention to provide a process for the manufacture of an improved pre-glued glass fabric wallcovering.
According to a preferred embodiment of the present invention, a wallcovering is produced by a process comprising the steps of providing a glass fabric, applying a first aqueous dispersion onto both sides of the glass fabric and forming dried coatings on both sides, and applying a second aqueous dispersion on the back side only of the fabric to create a thin dried layer which acts as the adhesive layer when the wallcovering is wetted for attachment to the wall.
While the preferred embodiment of the present invention utilizes glass fabrics in woven and rolled form, other fiberglass fabrics such as a nonwoven mats may be utilized.
Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, together with the accompanying drawings.